The inventive concept relates to a selection transistor and a method of fabricating the same.
Semiconductor memory devices for storing data can be classified into volatile memory devices and nonvolatile memory devices. Volatile memory devices may not preserve stored data without a power supply, but nonvolatile memory devices can preserve stored data even without a power supply.
A flash memory device, which is an example of a nonvolatile memory device, can electrically write and erase data, and can be appropriate for high density and large-scale information storage. In the flash memory device, a floating gate of a cell region unit device may be too thin to achieve high density and large-scale information storage. In this regard, as the floating gate functioning as a charge storage layer is reduced in thickness, it may be difficult to commonly form a gate of a string selection transistor (SST) or ground selection transistor (GST).